One-dimensional Cd metal string complex: Synthesis, structural and thermal properties of [(HPy)3(Cd3Cl9)]∞

The cadmium metal string complex of [(HPy)3(Cd3Cl9)]∞ (Py = pyridine) was prepared. Its structural and thermal properties were also investigated. Its existing form in gas phase has been elucidated by density functional calculations. The crystal structure consists of protonation pyridine cations and infinite one-dimensional chains of [Cd3Cl9]3− anions. Each Cd atom is octahedrally surround by bridged chlorine atoms, giving rise to polymeric chain along the a-axis. The pyridinium lie in the middle of the chain to balance the charge. The DFT study indicates that the HOMO orbital of optimized structure is mainly localized on the middle six chloride ions and the LUMO is delocalized. Differential thermal gravimetric analysis shows there is no presence of any structural phase transitions.